Forging press



July 21, 1970 w. BOTHE 3,521,415

FORGING PRESS Filed March 15, 1968 5 Sheets-$heet 1 INVENTOR WEE/V52507,95

:K l Toss July 21, 1970 w. BOTHE 3,521,475

FORGING PRESS I Filed March 15, 1968 3 Sheets-Sheet 5 FIG. 4

INVENTOR ATTORNEY United States Patent Office 3,521,475 Patented July21, 1970 3,521,475 FORGING PRESS Werner Bothe, Buderich, Germany,assignor to Maschinen-' Int. Cl. nzi 9/18 US. Cl. 72-429 7 ClaimsABSTRACT OF THE DISCLOSURE A forging press having a press frame and aflywheel eccentric shaft rotatable in the frame about a horizontal axisand having an eccentric portion surrounded by an eccentric ringswivelably connected to the forging head by a pressure-transmittingmember which is seated in an upwardly concave socket of the forging headand has a center of curvature located within the inner periphery of thering; the ring has an upper surface slidably bearing upon a portion ofthe forging slide, this portion having a center of curvature coincidingwith the center of curvature of the swivel member.

My present invention resides in a forging press having a support frame,a workpiece-supporting anvil, and a vertically shiftable head which isdisplaced by an eccentric shaft carrying a flywheel.

Forging presses which make use of an upstanding support frame or standin which an eccentric shaft or crankshaft is journaled generally provideguide means for a vertically shiftable press slide carrying, at itslower end, the forging head of the press and rods or the like connectingthe eccentric portion of the shaft to change the rotary motion of theshaft to linear motion of the slide toward and away from the anvil. Therods, pins and link members provided for this purpose must withstandconsiderable dynamic and static stress, vibration and shock and oftenare a weak point in the press construction. The rods also may be ofconsiderable length and thus have the tendency to bulk or otherwisedeform. Consequently, forging presses of this character require frequentrepair, expensive and highly skilled maintenance and are of relativelyexpensive construction.

It is an object of the present invention to provide a forging press inwhich the aforementioned disadvantages can be avoided, relatively highdynamic forces can be applied to a workpiece without danger of damage tothe moving parts, and which is of less expensive construction bycomparison with earlier presses.

Still another object of this invention is to provide aforce-transmitting system for a forging press or the like whichtransfers a maximum force or energy with a minimum of dangerof'breakdown or damage.

I have found that these objects can be obtained in a forging press whichomits the force-transmitting rods, pins and bars required heretofore andwhich simplifies the means for converting rotation of a crankshaft intovertical reciprocation of the press ,slide. According to a a circlecentered on the axis of rotation of the shaft and, moreover, establishesthe vertical stroke of the slide. Surrounding this cylindricaleccentric, I provide a ring within which the eccentric cylinder isrotatable and which carries a force-transmitting swivel having a swivelbody disposed directly between the cylindrical eccentric portion of theshaft and the forging head. This swivel body preferably has a downwardlyconvex portion of substantially cylindrical curvature which is receivedin an upwardly open trough or socket formed in the forging headcomplementarily to the cylindrical curvature of the swivel body. Themutually engaging surfaces of the socket and this body are centered uponthe swivel axis which, advantageously, lies within the outer peripheryof the cylindrical eccentric but is spaced from the axis of rotation ofthe shaft by a distance greater than that with which the axis of thecylindrical eccentric portion is distant therefrom. Thepressure-transmitting body thus may be constituted as a partial orsemicylinder although spherical or hemispherical shapes are alsopossible. Diametrically opposite the pressure-transmitting member, whichis affixed directly to the eccentric ring and constitutes part thereofas indicated earlier, I provide a segmental abutment whose outer surfaceis also centered on the axis of the swivel body and may engage acomplementary portion of the press slide dovetailed in a traverse abovethe eccentric shaft. The slide surfaces are likewise centered on theswivel axis.

This system has the advantage that all pressure-transmitting rods,toggle levers and the like can be avoided and that force is transmittedwith a maximum of directness from the shaft to the workpiece. Inaddition, minimum force is required to lift the slide from the workpieceduring the return stroke and the forces applied to the traverse uponwhich the eccentric acts in the return stroke are relatively small.

The above and other objects, features and advantages of the presentinvention will become more readily apparent from the followingdescription, reference being made to the accompanying drawing in which:

FIG. 1 is a vertical elevational view, partly in axial cross-section, ofa forging press in accordance with the present invention;

FIG. 2 is a cross-sectional view along the line II-II of FIG. 1;

FIG. 3 is a cross-sectional view of a portion of the device of FIG. 2showing the pressure-transmitting member in another position; and

FIG. 4 is a cross-sectional view along the line IVIV of FIG. 1.

In the drawing, I show a forging press which comprises a press stand orframe 1 whose posts or legs 1a, 1b, etc. are held together by a solidcrosspiece 1c and define guides in a conventional manner for thevertically shiftable press slide 3 which has a forging head 3a adaptedto be advanced toward an anvil 2 and withdrawn there from during thepress stroke. Through an opening 15 between the posts or legs 1a, 1b,etc., a workpiece may be inserted between the head 3 and the anvil 2 forforging action. 7

The drive for the slide 3 comprises an eccentric shaft 4 whose axis ofrotation in the support 1 is represented at arrow A and which is drivenby conventional means (e.g. a unirotational belt and pulley system,etc.) and is provided with a flywheel 16. Means .for adjusting the throwof the crankshaft is constituted by the gears 17 and the control member18 which function as described in my commonly assigned copendingapplication (now abandoned) Ser. No. 713,376 filed concurrently herewithand entitled Forging Press With Adjusting Means. The shaft 4 passesthrough the slide which is formed with a traverse across its top. At acentral location along the shaft 4, the eccentric shaft is provided withan eccentric 5 whose cylindrical surface 5a is centered on the axis Boffset radially from the axis A. The eccentric is surrounded by a ring 6forming part of a force-transmitting swivel 6-8 which includes a solidbody 7 of crescentshaped cross-section. This body 7, which is welded tothe balance of the ring 6, has an inner surface 7a corresponding to theouter cylindrical surface 5a and completes the ring 6. The body 7constitutes the sole forcetransmitting member between the eccentric 5and the head 3a which is formed with an upwardly concave socket 19 inwhich the convex portion 8 of the body '7 is received. The surfaces ofportion '8 and socket 19 are generally cylindrical and are centered uponthe axis 13 which constitutes the swivel axis of the device and isspaced from the axis A by a distance greater than the distance of axis Btherefrom. Diametrically opposite the body 7, ring 6 is provided with anabutment 9 of generally sectoral configuration whose surface 11 iscomplementary to the surface 12 of a slide dovetailed in the traverse10. Surfaces 11 and 12 are also centered upon the swivel axis 13.

During the operation of the press, rotation of shaft 4 about the axis Aswings the axis B about the axis A to describe the circle C. The swivelmeans 6, 7 and 8 is thus deflected as represented at at from side toside as the slide is raised and lowered. In its extreme positions, thebody 7 is aligned directly with the axis A, B and 13 (see FIG. 2) sothat maximum force transmission is ensured. During the return stroke,member 9 acts against the traverse 10 to lift the slide. Best resultshave been found to be obtainable when the center of curvature 13 of thesurface A lies within the surface 50, i.e. with the eccentric 5.

I claim:

1. A forging press comprising an upright support, an anvil, a pressslide vertically shiftable on said support toward and away from saidanvil, said slide being formed with a forging head engageable with aworkpiece disposed on said anvil, a shaft journaled on said support forrotation about an axis of said shaft and carrying a cylindricaleccentric with an axis spaced from the axis of the shaft and describinga circular path upon rotation of the latter, and force-transmittingswivel means engaging said eccentric and connected with said head whileincluding a solid force-transmitting body interposed directly betweensaid eccentric and said head, said forcetransmitting swivel meanscomprising a ring surrounding said eccentric with said eccentric beingrotatable within said ring, said body being affixed to said ring, saidring and said body defining a swivel axis spaced from the axis of saidshaft and said eccentric, said body having a convex portion centered onsaid swivel axis and said head being formed with a concave socketcomplementarily receiving said convex portion, said socket and saidconvex portion having mutually contacting surfaces centered on saidswivel axis and said swivel axis lying within the outer periphery ofsaid eccentric.

2. A forging press as defined in claim 1 wherein said mutuallycontacting surfaces are generally cylindrical.

3. A forging press as defined in claim 1 wherein said mutuallycontacting surfaces are generally spherical.

4. A forging press as defined in claim 1 wherein said ring is formed ata location diametrically opposite said body with an arcuate bearingsurface acting upon said slide for movement thereof away from saidanvil, said surfaces being centered on said swivel axis.

5. A forging press as defined in claim 4 wherein said slide is formedwith a traverse engageable by said bearing surface.

6. A forging press as defined in claim 1 wherein said swivel axis isspaced from the axis of rotation of said shaft by a distance greaterthan the distance between the axis of said shaft and the axis of saideccentric.

7. A forging press as defined in claim 1 wherein said shaft passesthrough said slide and is provided with a flywheel.

References Cited UNITED STATES PATENTS 999,276 8/1911 Thorp 724521,295,189 2/1919 Morgan 72429 2,232,889 2/1941 Spencer 72450 2,256,9089/1941 Rafter 72450 2,633,094 3/1953 Muller 72429 3,064,559 11/1962Theer -292 CHARLES W. LANHAM, Primary Examiner G. P. CROSBY, AssistantExaminer US. Cl. X.R. 72446, 450, 452

